This should be fixed now, but keep in mind "a viewer can see the old handle on a post/article for up to ~5 minutes after it moves, but it's bounded, self-healing (fixes within seconds of the next view once the window elapses), and purely cosmetic — earnings and payouts follow the account's address, never the handle, so nothing is ever misattributed during that window."
@cain, bug? If someone puts their PoW handle for sale, old articles point to the original wallet.